Physical and chemical properties of resveratrol

Resveratrol (3-4 '-5-trihydroxystilbene) is a non flavonoid polyphenolic compound, with the chemical name 3,4', 5-trihydroxy-1,2-diphenylethylene (3,4 ', 5-stilbene), molecular formula C14H12O3, and molecular weight 228.25. The pure appearance of resveratrol is a white to light yellow powder, odorless, insoluble in water, and easily soluble in organic solvents such as ether, chloroform, methanol, ethanol, acetone, and ethyl acetate. Its melting point is 253-255 ℃ and sublimation temperature is 261 ℃. Resveratrol can appear red in alkaline solutions such as ammonia, and undergo a color reaction with ferric chloride potassium ferrocyanide. This property can be used to identify resveratrol. [3]
Natural resveratrol has two structures: cis and trans. In nature, it mainly exists in the trans conformation, which can bind to glucose to form cis and trans resveratrol glycosides. Both cis and trans resveratrol glycosides can release resveratrol through the action of glycosidases in the intestine. Under UV irradiation, trans resveratrol can be converted into its cis isomer. The molecular formulas of resveratrol and its glycosides are shown in Figure 1.
Resveratrol produces fluorescence under 366nm ultraviolet light irradiation. Jeandet et al. determined the UV spectral characteristics of resveratrol and its infrared absorption peaks at 2800-3500 cm (OH bond) and 965 cm (trans double bond). Experimental results have shown that as long as light is completely isolated, trans resveratrol remains stable even after several months of storage, except in high pH buffer solutions.